Price comparator



United States Patent [72] Inventor James S. Luster 7111 Galewood St'.,San Diego, Calif. 92120 [21'] Appl. No. 771,874

[22] Filed Oct. 30, 1968 [45] Patented Dec. 29, 1970 [54] PRICECOMPARATOR 1 Claim, 4 Drawing Figs.

[52] U5. Cl 235/88 [51] lnt.C| G06c3/00 [50] Field ofSearch 235/84, 78,88

[56] References Cited UNITED STATES PATENTS 2,595,299 5/1952 Russell235/84 2,852,193 9/1958 Vaughen 235/84 2,871,582 2/1959 Frank 235/84X3,275,235 9/ I966 Balch 235/84 3,309,017 3/1967 Koskela 235/78 3,397,8388/1968 Ostranderetal. 235/70 OTHER REFERENCES Products: What's NewestSupermarket Slide Rule.

Newsweek, July 31,1961, p. 63.

Primary Examiner-Richard B. Wilkinson Assistant Examiner-Stanley A. WalAttorney-Carl R. Brown ABSTRACT: A price comparator for comparing unitpriceweight ratios of a commodity in difierent size containers, whichcomparator has a separate pair of aligned unit-weight and unit-pricelogarithm scales in which the price and weight of the commodity in agiven size container is placed on one of the price-weight scales and theprice and weight of the commodity in a second different size containeris placed on the other price-weight scale, and an indicator on the pricecomparator displays which container has the lower price per unitweightof the commodity.

PRICE COMPARATOR BACKGROUND OF THE INVENTION It is well known that anidentical or substantially identical commodity such as food, oil, soap,or any other commodity, is often sold in packages or containers havingdifferent sizes and prices. The weight or volume of the commodity in thepackage or container, as well as the price, is usually listed on thecontainer. So a price-weight comparison can be made. While ostensiblythe price for the contents in different size packages or containers isproportional to the unit price-weight of the contents, it is well knownthat the unit price-weight ratio varies considerable for different sizepackages or containers of the same commodity. Thus while purchaserswould normally assume that for a larger package or container, the unitpriceweight ratio would be lower than the unit price-weight ratio ofsmaller packages, considering the possible added packaging costs,pricing practices are such that this is not always true. So to theconsumer, the unit price-weight ratio is an important consideration inmaking purchases of the same or similar commodities in different sizecontainers.

The making of unit price-weight ratio comparisons normally involvesdifficult mathematical computations that the consumer is not prepared tomake at the time of purchase. This is especially true where housewivesare purchasing articles of food in supermarkets and where the. weightorvolume of similar commodities are alternatively designated in ounces,pounds, fluid ounces, pints, quarts, and like measures. Thus theconsumer is often faced with purchasing alarger package or container ofa given commodity upon the assumption that the unit price-weight ratiois lower than the unit price-weight ratio of a smaller container, eventhough'the consumer would rather purchase the commodity in the smallercontainer Further. consumers often want to compare unite price-weightratios of difi'erent brands of the same commodity, which differentbrands are packaged in different size packages.

Thus it is advantageous to have an inexpensive and simple to operateprice comparator on which the information relative to unit price-weightor unit price-fluid volume of packaged commodities can be easily andquickly compared and that will immediately display which package isthebetter buy.

SUMMARY OF THE INVENTION The price comparator of this inventionfunctions to compare unit price-weight ratios or unit price-fluid volumeratios of different size packages or containers of the same or similarcommodities. The price comparator has a first aligned weight scale andprice scale and a second weight scale and price scale, on which the unitprice-weight ratios of various given packaged commodities can becompared. A base member has a pair of opposed, half circle logarithmscales of units of weight and units of fluid, that together form acircle. Separate first and second circular discs are connected at theircenters in layers on the base member. Each of the discs rotateindependently of each other and independently of the base member andhave smaller diameters than the diameter of the unit weight scales onthe base member. The discs each have a unitprice scale that is scaledlogarithmically around one side edge and is positioned adjacent one ofthe two unit weight scales on the base member. Thus one unit pricelogarithmic scale of one of the discs is positioned adjacent one of theunit weight logarithmic scales on the base member and the unit pricelogarithmic scale of the other disc is positioned adjacent the otherunit weight scale on the base member. The upper disc member or thesecond disc member has a recessed circumferential edge that opens toview the unit price scale of the intermediate or first disc member. Thesecond disc member has oppositely directed, triangular shaped slots thatopen to the surface of the first disc The first disc has a given coloredsurface that covers a substantially semicircular portion of the firstdisc surface.

In use, the unit price of two packages of a given commodity versus itspackaged weight or its fluid content are set in aligned relationship onthe first and second adjacent priceweight scales. Should there be adifference in commodity unit price versus weight or fluid contentbetween the commodities in two packages or containers, then thecommodity package having the lowest unit price-weight ratio is displayedby a portion of the colored surface on the first disc appearing in theslot in the second disc that is adjacent the corresponding scale.

Thus by quickly aligning the respective unit price-weight listings forthe different packages, the lowest unit price-weight package is quicklyindicated in the display on the price comparator. Thus it may be seenthat the price comparator provides in a simple and effective manner; aquick determination of which package has the lower commodity unit cost.

It is therefore an object of this invention to provide a new andimproved price comparator for comparing commodity unit price-weightratios in different size packages and containers.

It is another object of this invention. to provide a new and improvedprice comparator for comparing unit price-weight ratios of differentweights or sizes of packages of a given commodity that is simple inoperation, inexpensive to make, and that displays the lowest unitprice-weight ratio without requiring mathematical computations.

It is another object of this invention to provide a new and improvedprice comparator for comparing unit price-weight or fluid content ratioof different size packages or containers in which the weight or fluidcontent is listed in ounces, pounds, fluid ounces, pints, quarts andlike units of measure.

Other objects, novel features and advantages will become more apparentupon a reading of the following detailed specification and anexamination of the drawings in which:

FIG. I is a top plan view of an embodiment of this invention. FIG. 2 isa cross-sectional view taken along lines 2-2 of FIG. 1.

FIG. 3 is a top plan view of an embodiment of this invention withportions broken away.

FIG. 4 is a top plan view of an embodiment of this inventionillustrating the operation of the invention.

Referring to FIGS. 1 and 2, the embodiment of the price comparator has arectangular base member 11 with a flrstcircular disc 16 and a secondsubstantially circular disc 24 secured thereto by a known rivetconnection 26 that allows independent rotational movement between eachof the discs and the base member. The base member 11 and the discs 16and 24 may be constructed of any suitable materials, such as plastic,paper, metal, or other suitable sheet materials. The base member has apair of unit-weight logarithm scales 40 and 42' that are illustrated toextend between 2 ounces and 10 pounds. The respective weight scales arecircularly arranged on the base member with the increase scale directionbeing clockwise for each scale. The first disc 16 has a circular shapewith a logarithm unit price scale 30. The curved unit price scale 30 hasa range of $.10 to $2.00 and is positioned to cooperate with the unitweight scale 42. The outer disc member 24 has an identical unit pricelogarithm scale 28 that is positioned on the opposite side of the disc24 in a position to cooperate with the unit weight scale 40. The disc 24has a slotted or recessed portion around its outer edge 44 that permitsviewing of the unit price scale 30 on the disc 16. The second disc 24also has triangular slots 36 and 38 that pass through the disc structure24 and permits viewing the surface of the first disc 16.

It should be recognized that the respective price, weight and fluidunits used in the embodiment scales are only illustrative of aparticular area of purchasing costs of which the majority of thehousewife consumers are involved; and any suitable price, weight andfluid ranges can be employed in the logarithm scales.

The price comparator l0 employs colors to effectively improve the use ofthe comparator and the correlation and display of readings from theprice comparator giving an instantaneous display of the bestprice-weight ratio. For example, the area 12 on the base member 11 maybe orange in color and the area 14 on the base member 11 may be green incolor. With this color arrangement, the area 34 on disc 24 is green andthe area 32 on disc 24 and the scale area bounded by lines 18 and ondisc 16 is orange. The remainder of the upper surface of the disc 16,see FIG. 3, has a green area 64, an orange area 62, and a black area 60.The black area is substantially semicircular with edges 66 that arealigned with the upper edges of the triangular slots 36 and 38, when thetriangular slots are positioned in alignment with lines 66. Thus in thenormal or first position, the green side 34 has a green color in theopening 36 corresponding to the green section 64 of the upper surface ofdisc 16. The orange side 32 displays an orange color in slot 38corresponding to the orange section 62. When the discs 16 and 24 arerotated to align given prices with given weights on the scales, in themanner that will be described in more detail hereinafter, slot 36 orslot 38 will move into the black portion 60 depending upon which of theunit price-weight ratios is the lowest of the commodities compared, andthe black color in the slot shows which container has the lowest unitprice for the commodity.

In operation, the consumer may for example, be contemplating thepurchase of cans of tuna fish. One can of tuna fish has a content weightof 6% ounces and a cost of $.27 per can. The other can of tuna fish hasa contents weight of 12 ounces and costs $.55 per can. In this example,the consumer would rather buy the smaller can of tuna fish for variousreasons, however the purchaser desires to purchase the lower unitprice-weight of tuna fish. Accordingly, the purchaser, see FIG. 4, setsthe $.27 mark on the orange price scale 30 of disc 16 to the 6% ouncemark on the orange scale 42 on the base member 11. The purchaser-thensets the $.55 mark on the green price scale 28 of disc 24 to the l2/2ounce mark on the green weight scale 40 on base 11. It may be observedthat this movement has caused disc 24 to move in a counterclockwisedirection relative to disc 16 causing slot 38 to pass into the blackportion 60 of the disc 16. Thus the black color 39 in slot 38immediately displays to the purchaser that the orange side of the scalehas the lowest unit price-weight ratio, and thus the price per ounce fortuna fish is lower for the 6% ounce can than for the 12% ounce can. Themore black area that is dis played in slot 38, the larger thedifferential in unit priceweight ratio.

It may be understood that similar comparisons can be made betweenweights involving ounces or pounds or between units of fluid involvingfluid ounces, pints and quarts.

Iclaim:

I. A price comparator for comparing unit price-weight ratios and unitprice-fluid volume ratios of commodities in different size containerscomprising:

a base member and two circular discs joined in layers and at theircenters to rotate independently of each other;

one surface of said base member has units of weight and fluidlogarithmically scaled thereon in a pair of identical in size and scaleunits circularly arranged separate half circular scales that aresymmetrically arranged in diametrically opposed positions;

a first one of said discs has a diameter less than the diamete of saidunits of weight scales and has units of price scaled logarithmically ina first price scale around one side edge that is adjacent to one of saidunits of weight scales forming a first price-weight ratio designation;

a second one of said discs has a diameter less than the diameter of saidunits of weight scales and has units or price scaled logarithmically ina second price scale around one side edge that is adjacent to the otherof said units of weight scales forming a second price-weight ratiodesignation;

display means responsive to the relative alignment of said first andsecond discs as a result of a given first priceweight ratio designationand a given second price-weight ratio designation for displaying theprice-weight designation having the lowest price-weight ratio;

said first and second discs have substantially the same circular shape;the side edge of said second disc opposite said second price scale isrecessed around the curved edge to uncover the first price scale of saidfirst disc;

said first price scale on said first disc is identical in size and scaleunits with said second price scale on said second disc;

said display means comprises spaced slots through said second disc;

one of said slots is positioned adjacent the center of said units ofprice scale on said second disc and said other slot is positioned on theopposite side of the center of said disc in symmetrical alignment withsaid one slot;

the surface of said first disc adjacent said second disc has a coloredarea that solely displays through one of said slots which price-weightratio designation has the lowest priceweight ratio; I

said colored area on said first disc covering substantially asemicircular area with radial edges that are substantially aligned withthe upper edges of said slots; and

and whereby any relative movement between said discs causes at least aportion of said colored area to be displayed in one of said slots.

